I don't have any power on my F pin ( light green wire) of my park position switch. How can I test and track the cabling to resolve the issue?

What is your question?

My backup lights quit working suddenly and now I have no power coming from the F pin on the 7 pin connector of my transmission position switch.

What makes this problem better or worse?

Nothing I've noticed.

How long has your 1995 Chevrolet C1500 had this problem?

The lights were working a few days ago and quit.